Laser‐fired contact for n‐type crystalline Si solar cells

He, Jianbo; Hegedus, Steven; Das, Ujjwal; Zhang, Shu; Bennett, M.; Zhang, Lei; Birkmire, Robert W.

doi:10.1002/pip.2520

Cited by 26 publications

(7 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As an application of laser firing on a silicon heterojuction architecture with n-type bulk, it may be of interest to other groups working on industry-relevant fabrication techniques for IBC or SHJ-IBC architectures [7,8]. Complementary works on laser firing on IBC cells include n-type dopant sources such as POCl 3 , Sb, phosphorous doped silicon carbide (a-SiC x (n)) or phosphorous spin-on dopants [8,9,10,11].…”

Section: Introductionmentioning

confidence: 99%

Laser firing in silicon heterojunction interdigitated back contact architecture for low contact resistance

Garud

Trinh

Rhein

et al. 2019

Solar Energy Materials and Solar Cells

View full text Add to dashboard Cite

This work reports a laser firing technique applied to completed silicon heterojunction interdigitated back contact solar cells in order to lower contact resistance. Previously, the implementation of a-Si:H(i) at the electron contact of polycrystalline silicon solar cells on glass substrates led to an increase in series resistance. The cell architecture with the current record efficiency of 14.2 % (with illumination through glass) utilizes only an a-Si:H(n+) layer and 2 −2.9 mA cm −2 of short circuit current density is lost due to electrical shading under the electron contact [1],[2]. The goal of implementing an a-Si:H(i) layer and laser firing at this contact is to achieve low contact resistance at fired spots while preserving a-Si:H(i) passivation in unfired regions. After the laser firing, V OC was retained, while up to 14 % absolute increase in FF was obtained with a mere 0.2 mA cm −2 loss in J SC. In the best performing cell, a 72.1 % FF was achieved with a 0.7 mA cm −2 loss in J SC. Two laser sources were used to first ablate a part of the silver contact metal, and then to laser fire through the Si(n)/a-Si:H(i/n+)/ITO/Ag contact. The optimal laser fluence was found to be 1.1 −0.5 J cm −2 (355 nm, picosecond pulse duration) and 4.4 −5.2 J cm −2 (532 nm, nanosecond pulse duration), respectively. The upper limit on specific contact resistance in the laser fired spots was calculated to be 38 ± 20 mΩ cm 2 as a conservative estimate.

show abstract

Section: Introductionmentioning

confidence: 99%

Laser firing in silicon heterojunction interdigitated back contact architecture for low contact resistance

Garud

Trinh

Rhein

et al. 2019

Solar Energy Materials and Solar Cells

View full text Add to dashboard Cite

show abstract

“…The capex associated with contact firing can be reduced for a traditional belt furnace process by increasing the throughput of the entire manufacturing process (the throughput of a belt furnace is just determined by the belt length). Belt furnace firing can also be replaced by laser-firing [53][54][55] or another more efficient furnace. 56,57 On the module level, capex can be reduced by eliminating the aluminum frame 27,58,59 and simplified tabbing and stringing of cells together.…”

Section: Papermentioning

confidence: 99%

Economically sustainable scaling of photovoltaics to meet climate targets

Wilson¹,

Needleman²,

Poindexter³

et al. 2017

2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)

View full text Add to dashboard Cite

To meet climate targets, power generation capacity from photovoltaics (PV) in 2030 will have to be much greater than is predicted from either steady state growth using today's manufacturing capacity or industry roadmaps. Analysis of whether current technology can scale, in an economically sustainable way, to sufficient levels to meet these targets has not yet been undertaken, nor have tools to perform this analysis been presented. Here, we use bottom-up cost modeling to predict cumulative capacity as a function of technological and economic variables. We find that today's technology falls short in two ways: profits are too small relative to upfront factory costs to grow manufacturing capacity rapidly enough to meet climate targets, and costs are too high to generate enough demand to meet climate targets. We show that decreasing the capital intensity (capex) of PV manufacturing to increase manufacturing capacity and effectively reducing cost (e.g., through higher efficiency) to increase demand are the most effective and least risky ways to address these barriers to scale. We also assess the effects of variations in demand due to hard-to-predict factors, like public policy, on the necessary reductions in cost. Finally, we review examples of redundant technology pathways for crystalline silicon PV to achieve the necessary innovations in capex, performance, and price. Broader context To reduce CO 2 emissions enough over the next fifteen years and avoid the worst effects of climate change will require dramatic increases in the deployment of renewable energy, photovoltaics (PV) in particular. Climate action plans call for 2-10 terawatts (TW) of PV by 2030. Current manufacturing capacity could supply enough for 1 TW of cumulative installations at the end of this period, implying that growth in manufacturing capacity is necessary. Industry roadmaps project up to 2.6 TW but largely fail to assess whether these targets are economically feasible with today's PV module technology. Addressing the question of what technological innovations, if any, would enable rapid manufacturing scale-up requires a conceptual advance in modeling methodology. We address this challenge by coupling three industry-validated models: a bottom-up cost model, an economically sustainable growth-rate calculator, and a constraining demand curve. This approach enables us to determine the sensitivity of PV industry growth to specific technological and economic variables, considering both their effect on the ratio of up-front factory costs to revenue and demand as a function of PV module price. Shifting the demand curve enables us to consider the effects of different policy decisions, like a carbon tax or deployment subsidies.

show abstract

Section: View Article Onlinementioning

confidence: 99%

Economically sustainable scaling of photovoltaics to meet climate targets

Needleman

Poindexter

Kurchin

et al. 2016

Energy Environ. Sci.

View full text Add to dashboard Cite

aTo meet climate targets, power generation capacity from photovoltaics (PV) in 2030 will have to be much greater than is predicted from either steady state growth using today's manufacturing capacity or industry roadmaps. Analysis of whether current technology can scale, in an economically sustainable way, to sufficient levels to meet these targets has not yet been undertaken, nor have tools to perform this analysis been presented. Here, we use bottom-up cost modeling to predict cumulative capacity as a function of technological and economic variables. We find that today's technology falls short in two ways: profits are too small relative to upfront factory costs to grow manufacturing capacity rapidly enough to meet climate targets, and costs are too high to generate enough demand to meet climate targets. We show that decreasing the capital intensity (capex) of PV manufacturing to increase manufacturing capacity and effectively reducing cost (e.g., through higher efficiency) to increase demand are the most effective and least risky ways to address these barriers to scale. We also assess the effects of variations in demand due to hard-to-predict factors, like public policy, on the necessary reductions in cost. Finally, we review examples of redundant technology pathways for crystalline silicon PV to achieve the necessary innovations in capex, performance, and price. Broader contextTo reduce CO 2 emissions enough over the next fifteen years and avoid the worst effects of climate change will require dramatic increases in the deployment of renewable energy, photovoltaics (PV) in particular. Climate action plans call for 2-10 terawatts (TW) of PV by 2030. Current manufacturing capacity could supply enough for 1 TW of cumulative installations at the end of this period, implying that growth in manufacturing capacity is necessary. Industry roadmaps project up to 2.6 TW but largely fail to assess whether these targets are economically feasible with today's PV module technology. Addressing the question of what technological innovations, if any, would enable rapid manufacturing scale-up requires a conceptual advance in modeling methodology. We address this challenge by coupling three industry-validated models: a bottom-up cost model, an economically sustainable growth-rate calculator, and a constraining demand curve. This approach enables us to determine the sensitivity of PV industry growth to specific technological and economic variables, considering both their effect on the ratio of up-front factory costs to revenue and demand as a function of PV module price. Shifting the demand curve enables us to consider the effects of different policy decisions, like a carbon tax or deployment subsidies.

show abstract

Laser‐fired contact for n‐type crystalline Si solar cells

Cited by 26 publications

References 22 publications

Laser firing in silicon heterojunction interdigitated back contact architecture for low contact resistance

Laser firing in silicon heterojunction interdigitated back contact architecture for low contact resistance

Economically sustainable scaling of photovoltaics to meet climate targets

Economically sustainable scaling of photovoltaics to meet climate targets

Contact Info

Product

Resources

About